Electric signal receptacle and plug



m. 25, was. c. AUTH 2,0329% ELECTRIC SIGNAL RECEPTAGLE AND PLUG Filed March 10, 1935 INVENTOR I Charles Aufh wd wv new ATTORN YS Patented Feb. 25 1936 NITED STATES PATENT OFFICE Application March 10,

17 Claims.

This invention relates particularly to improvements in electric signal receptacles and plugs intended'for use in hospital calling systems. Itis customary in such systems to install wall receptacles provided with terminals connected to various annunciator or lamp signal stations, and to provide defachable plugs with cord switch devices to be used with these receptacles. The patient may call by operating the cord switch device. Mechanism is provided, however, for making the call automatic in case the plugrbecomes accidentally detached or removed from the wall receptacle, in which case of course the cord switch becomes useless unless it is possible for i the patient to replace the plug.

The main object of my invention is the provision of improved means associated with an electric signal receptacle and plug for automatically closing the various circuits which are normally closed by the cord switch, upon detaching or removing the plug from the receptacle. More specifically, the main object of my invention is to provide positive means for moving a circuit closer cooperating with contacts in the receptacle into circuit closing position as the plug is removed from the receptacle, and into circuit breaking position as the plug is inserted into the receptacle. Further provision consists in means for facilitating operation of the circuit closer into circuit closing position in cases in which the plug is removed by a lateral pull on the plug by the cord.

Other objects of the invention consist in the construction and arrangement of the cord terminals and contact fingers of the plug, and the cooperating spring contacts and terminal contact plates in the receptacle to provide for proper insulation between the various parts, to provide for the use or relatively strong terminals, and to provide a construction in which the contacts on the plug are not liable to be bent when the plug is dropped on the floor.

Other objects of the invention will appear from the following description taken in connection with the drawing, in which Fig. 1 shows a rear View of the plug and a face view of the receptacle supported in the face plate of the usual box receptacle;

Fig. 2 is a longitudinal central diametral section through a plug and receptacle showing the circuit closer in circuit opening position;

Fig. 3 is a view partly corresponding to the view shown in Fig. 2 with the plug detached and the circuit. closer. in circuit closing position;

1933, Serial No. 660,231

Fig. 4 is a rear view of the receptacle as viewed through the rear glass cover plate; and

Fig. 5 shows a circuit closer and operating means therefor with one of the fingers of the circuit closer in contact with a contact on one of the U-shaped terminal contact plates of the receptacle.

The face plate In for the wall box not shown, may be of any suitable construction and may, if desired, be provided with the usual local signal light and with a hole to receive the electric signal receptacle II. The plug 12 comprises two insulating members I 3 and I 4 which may be held together by radially extending screws, not shown. The outer member I3 is provided with an interior flange against which the inner member I4 is seated, as shown in Fig. 2, and also with a circular flange spaced from said shoulder providing a space for receiving a fiber collar or washer l5 tightly surrounding the cover of the chord l6. The signal cord l6 has a live rubber exterior covering and also interior covering for the individual conductors. The fiber washer has a hole slightly smaller in diameter than the normal outside diameter of the cord and, therefore, when the cord is drawn through it, it compresses the outer covering of the cord. The washer is so positioned with respect to the end of the cord covering that the operation of inserting part l4 into part 13 causes a compression of the cord between the washer and part M which causes the rubber covering of the cord to flare widely on the side of the washer adjacent to I 4. The result of this flare is that when tension is placed on cord 16 the force acts on the flare of the outer covering of the cord which acts on washer I5 whichinturn acts on part l3. Thus, the tensile strain which would be sufiicient to pull the conductors of the cord from the terminals 20, is prevented-from acting on the conductors at all, and-it is taken entirely by the outer covering of the cord.

'The end of the cord may be equipped with a switch device I? by means of which the various wires in the cord are connected together to close circuits for controlling signaling devices indicating the room or place from which the signal is transmitted.

, The inner member I4 of the plug is provided with radial webs I 8 providing recesses within which the ends of. the cord wires are fastened to the contact fingers IQ of the plug by screws 20. The contact fingers; I 9 are preferably rectangular in cross section and of thegeneral contour shown in Fig. 2... .and include shanks which extend through and. closely fit longitudinally ei'ctending openings in the member M, as shown in Figs. 1, 2 and 3. Each contact finger is provided with spaced pairs of oppositely facing shoulders which rest on corresponding shoulders on said member M, as shown in Fig. 2. The faces of the radial fins on said member M are grooved to receive the upper wide extension of the fingers i9, as shown in Fig. 2. The construction described provides for rigidly securing the fingers to the plug and provides a large space for access to the terminal screws 28, the space being sufficient to permit the ends of the wires of several cords to be secured to said fingers. The construction also provides for proper insulation between the various wires of the cord and the contact fingers.

In the construction described, the radially extending fins on the member M are of substantial width so that the fingers when secured in position against corresponding sides of the radial fins will lie in planes spaced from and parallel to the central radial planes of the fins. By means of this construction the ends of the contact fingers H extending forward of the plug |2 will be so disposed With respect to the periphery of the plug that the direction of the force of impact on the contact fingers, as the plug is dropped, will be at an angle to a line normal to the width of the contact fingers.

The arrangement of the contact fingers I9 provides room for a cylindrical split socket 2! arranged axially therein, as shown in Fig. 2. The ends of the fingers of this socket are preferably bent toward each other to grasp and frictionally engage the ball-shaped end 22 of a circuit closer operating rod 23 which is mounted in the receptacle for moving a circuit closer 24 into circuit closing position. The ends of the fingers of the socket member 2| are also arranged to engage with a circuit closer operating sleeve 25 for moving the circuit closer 24 into circuit opening position.

The electric signal receptacle comprises an insulating member 26 in which the circuit closer and operating members therefor are slidably supported. The member 26 is provided with a reduced forward end to fit in the opening in the face plate iii of the box receptacle. This member 26 may be provided with arms 21 by means of which it may be secured to the face plate It], as indicated in Figs. 2 and 4. The arms are preferably so related to the front face of the receptacle I l as to provide room for several spacing washers whereby the face of the receptacle may be 7 brought flush with the face of the face plate It).

As indicated in Figs. 1, 2 and 3, the electric signal receptacle H is provided with a central aperture for slidably receiving the operating sleeve 25 and the circuit closer 24 before referred to, and with apertures disposed to receive the.

contact fingers I9 of the plug. The outer configuration of the receptacle 26 is substantially the same as that of the member M of the plug providing recesses 28 for receiving screws 29 by means of which the outgoing wires are secured to' terminal contact plates 30 which may be of genthe same shape as the terminal contact plate 30 which also is seated in recesses in the outer and end faces of said walls. The construction is such that when the parts are in assembled position the outer faces of the members 3| will lie in the same plane as the end faces of the walls referred to.

Each of the terminal plates 30 is provided with a contact 32 with which a finger 33 of the circuit breaker 24 cooperates when the circuit breaker is in functioning position, as shown in Fig. 3. The contacts 32 also cooperate with shoulders on the free ends 34 of the spring contact members 3| to brace the ends 3 3 as the contact fingers IQ of the plug are inserted in position between the ends of the spring contact members 3| and the terminal contact plates 30. The ends 34 of the spring contact members 3| are preferably provided with inwardly struck portions to cooperate with correspondingly shaped depressions in the contact fingers I9 by means of which the plug is held in position within the receptacle.

An insulating plate 35, preferably of glass, is secured to the member 25 by screws as indicated. This plate constitutes a means for holding the terminal contact plates and cooperating spring contact members in position. The plate 35 is provided centrally with an aperture for loosely receiving the reduced bearing end 36 of the operating rod 23 so that the member 23 may accommodate itself to the movement of the plug when the plug is pulled out of the socket by a sidewise pull. The plate 35 constitutes a stop cooperating with the enlarged cylindrical portion 31 of the operating rod 23 to limit the rearward movement of the rod 23, as indicated in Fig. 2, so that the ball-shaped forward end 22 may be grasped by the socket 2| as the plug is inserted in a receptacle.

When the plug is removed from the receptacle, that is, from the position shown in Fig. 2 to the position shown in Fig. 3, the pull of the socket 2| on the ball-shaped end 22 of the operating rod 23 moves the circuit closer 24 and the sleeve 25 into the position shown in Fig. 3, in'which position the fingers 33 of the circuit closing member 22 contact with the contacts 32 on the terminal contact plates 36, thus short-circuiting all the circuit connections connected to said terminal plates to operate the desired indicating devices.

When the plug is inserted in the receptacle the forward end of the socket member 2| presses on the sleeve 25 which pushes the circuit breaker 24 rearwardly into the position shown in Fig. 2.

The circuit breaker 24 and the operating members 23 and 25 will remain in the position shown in Figs. 2 and 3 due to friction between the operating sleeve 25 and the circuit closer 24 and the cooperating parts of the receptacle 26. As indicated in Figs. 2 and 3, the central opening of the receptacle is provided with a shoulder with which a shoulder on the sleeve 25. cooperates to limit the forward movement of the operating rod, the operating sleeve and the circuit closer. For the purpose of preventing rotational movement of the circuit closer 2% the opening within the receptacle receiving the circuit closer is preferably provided with grooves within which the spring fingers 33 of the circuit closer 23 operate.

By means of the construction disclosed I have provided a circuit closer whose operation does not depend upon any spring operation, and which is constructed and mounted within the receptacle in such a manner that it is held in either of its positions by sliding frictional contact with the receptacle.

As stated before. the circuit closer is moved into circuit opening position upon insertion of the plug. It may also be moved into circuit opening position directly manually by pressing on the forward end of the sliding operating sleeve 25. The arrangement of the terminal contact plates 30, shown in Fig. 4 and previously described, provides suflicient space for mounting the circuit closer and associated operating means centrally of the receptacle.

While the invention has been described in detail with respect to a particular preferred embodiment which gives satisfactory results, it will be understood by those skilled in the art, after understanding this invention, that various changes and modifications may be made without departing from the spirit and scope of the invention, and it is intended, therefore, in the appended claims to cover all such changes and modifications.

What I claim is:

1. In a receptacle comprising a plurality of terminal contact elements arranged symmetrically about the axis of said receptacle, said receptacle being provided with an axial bore and longitudinally extending grooves in the walls of said bore, a circuit closer slidably mounted within and having spring fingers frictionally engaging the bottoms of the grooves in the wall of said bore, and means accessible from the exterior of said receptacle for moving said circuit closer into circuit opening or circuit closing position, the frictional contact between the spring fingers of said circuit closer and the bottoms of the grooves in the wall of the receptacle functioning to hold said circuit closer in either of its positions.

2. In a receptacle comprising a plurality of terminal contact elements arranged symmetrically about the axis of said receptacle, said receptacle being provided with an axial bore, a circuit closer slidably mounted within and frictionally engaging the walls of said bore, and operating means accessible from the exterior of said receptacle for moving said circuit closer into circuit opening or circuit closing position, the frictional contact between said circuit closer and receptacle functioning to hold said circuit closer in either of its positions, said operating means comprising a rod and surrounding sleeve accessible from the exterior of the receptacle, said sleeve being provided with means for moving the circuit closer into circuit opening position and said rod being provided with means for moving the circuit closer into circuit closing position.

3. In a receptacle comprising a plurality of terminal contact elements arranged symmetrically about the axis of said receptacle, said receptacle being provided with an axial bore, a circuit closer slidably mounted within and frictionally engaging the walls of said bore, and operating means accessible from the exterior of said receptacle for moving said circuit closer into circuit opening or circuit closing position, the frictional contact between said circuit closer and receptacle functioning to hold said circuit closer in either of its positions, said operating means comprising a rod and surrounding sleeve accessible from the exterior of the receptacle, said sleeve being provided with means for moving the circuit closer into circuit opening position and said rod being provided with means for moving the circuit closer into circuit closing position, means on said sleeve and receptacle for limiting the forward movement of said sleeve and the movement of the circuit closer when moved into circuit closing position.

4. In a receptacle comprising a plurality of terminal contact elements arranged symmetrically about the axis of said receptacle, said receptacle being provided with an axial bore, a circuit closer slidably mounted within and frictionally engaging the walls of said bore, and operating means accessible from the exterior of said receptacle for moving said circuit closer into circuit opening or circuit closing position, the frictional contact between said circuit closer and receptacle functioning to hold said circuit closer in either of its positions, said operating means comprising a rod and surrounding sleeve accessible from the exterior of the receptacle, said sleeve being provided with means for moving the circuit closer into circuit opening position and said rod being provided with means for moving the circuit closer into circuit closing position, means on said sleeve and receptacle for limiting the forward movement of said sleeve and the movement of the circuit closer when moved into circuit closing position, said rod being provided with a shoulder engaging the circuit closer for moving the circuit closer into circuit closing position.

5. In a receptacle comprising a plurality of terminal contact elements arranged symmetrically about the axis of said receptacle, said receptacle being provided with an axial bore, a circuit closer slidably mounted within and frictionally engaging the walls of said bore, and operating means accessible from the exterior of said receptacle for moving said circuit closer into circuit opening or circuit closing position, the frictional contact between said circuit closer and receptacle functioning to hold said circuit closer in either of its positions, said operating means comprising a rod and surrounding sleeve accessible from the exterior of the receptacle, said sleeve being provided with means for moving the circuit closer into circuit opening position and said rod being provided with means for moving the circuit closer into circuit closing position, means on said sleeve and receptacle for limiting the forward movement of said sleeve and the movement of the circuit closer when moved into circuit closing position, said rod being provided with a shoulder engaging the circuit closer for moving the circuit closer into circuit closing position, said rod also being provided with a shoulder for limiting the movement of the circuit closer as it is moved into circuit opening position, and means on said receptacle cooperating with said last mentioned shoulder.

6. In a receptacle including a series of terminal contact elements and provided with a bore, a circuit closer movable within said bore from circult closing to circuit opening position, means extending exteriorly of said receptacle for moving said circuit closer into circuit opening position, and means also extending exteriorly of said receptacle for moving said circuit closer into circuit closing position, said last mentioned means having a loose connection with said circuit closer whereby it may assume positions at an angle to the longitudinal axis of said circuit closer.

'7. In a receptacle including terminal contact elements, and a circuit closer comprising a series of connected fingers frictionally engaging said receptacle and movable into and out of engagement with said contact elements, said fingers engaging said receptacle with sufiicient friction to hold 15 said circuit closer in its functioning or nonfunctioning position. ,v 8. In a receptacle including terminal contact elements, a circuit closer comprising a series of connected fingers frictionally engaging said receptacle and movable into and out of engageadapted to move into frictional engagement over said ball as the plug is inserted into said receptacle whereby the circuit closer will be moved into circuit closing position as the plug is detached from the receptacle.

10. The combination with a receptacle including a plurality of contact elements and a circuit closer movable into circuit closing and circuit opening position with respect to said elements, means projecting exteriorly of said receptacle for operating said circuit closer, said means comprising a rod and a surrounding sleeve, a plug provided with contact fingers, a member carried by said plug for direct contact with said sleeve for moving said circuit closer into circuit opening position as the plug is inserted in the receptacle, said member also having means for frictionally engaging said rod whereby said rod will be moved to move said circuit closer into circuit closing position upon detaching said plug from said receptacle.

11. The combination with a receptacle, a circuit closer movably mounted within said receptacle, a plug, and cooperating means on said plug and circuit closer for positively moving said circuit closer into circuit opening position as the plug is inserted into the receptacle and for positively moving said circuit closer into circuit closing position as said plug is removed from said receptacle.

12. The combination with a receptacle, a circuit closer slidably mounted within said receptacle, a plug adapted to be inserted in said receptacle, and means on said plug for moving said circuit closer into circuit opening position as the plug is inserted into said receptacle and for moving said circuit closer into circuit closing position as the plug is removed from the receptacle.

13. The combination with a receptacle provided with contact elements, a plug connected to said receptacle, a circuit closer within said receptacle, said circuit closer and contact elements being receptacle are connected, and means pivotally mounted within said receptacle and operated positively upon removal of said plug from said receptacle for moving said circuit closer and contact elements relatively into circuit closing relation.

15. In a receptacle, a circuit closer frictionally supported therein, a cooperating plug, and means cooperating with said circuit closer operable manually and by the insertion and removal of the plug for positively moving said circuit closer into either of its positions.

16. The combination of a receptacle provided with a plurality of fixed contact members, a movable circuit closer mounted in said receptacle, slidable from a position of no contact to one of contact and vice versa with said contact elements of said receptacle, means projecting exteriorly for operating said movable circuit closer, a plug provided with contact fingers for engagement with said contact members of said receptacle, cooperating means on said plug to make a separable connection with the exterior operating means of said circuit closer whereby the circuit closer will be positively moved to its no contact position by the insertion of the plug in the receptacle and positively moved to its contact position by the removal of the plug from the receptacle.

17. In a plug comprising an inner cylindrical member provided with a plurality of terminal contact plates arranged in a circular series about the axis of said member, an outer hollow cylindrical member provided with an end wall having an axial opening to receive a rubber covered electric cord, said opening being of smaller radius than the radius of the circle on which said contacts are located, a rubber covered elastic cord extending through said opening and having the terminals of its wires bent outwardly radially and secured to said plates, a washer fitted tightly on said cord at a point spaced a short distance from the free end of the rubber cover and located in the space provided between said end wall and the end of theinner member for contact against said end wall, the construction and arrangement of the parts being such that when the inner and outer members are assembled, the wires of the cord cause the free end of the rubber cover to flare to a larger diameter than the hole in the washer.

CHARLES AUTI-I. 

